The honor and responsibility that have been bestowed on me in receiving the MERIT AWARD have allowed us to solve one of most challenging problems related to the topics of vector molecular biology. The defining characteristic of anautogenous vector mosquitoes is their requirement for a blood meal to initiate reproduction. This requirement places strong evolutionary pressure upon anautogenous mosquitoes to make frequent host contacts and, as a consequence, makes them ideal disease vectors. The understanding of mosquito reproductive biology, the process responsible for driving disease transmission, is an important component in the development of novel strategies for use in mosquito-borne disease control. The major achievement of this project has been the breakthrough discovery of the molecular mechanism underlying the physiological reproductive block of the egg development, which in anautogenous mosquitoes is regulated by amino acids (AA/TOR parhway) from the ingested vertebrate blood. The goal of research for the next five years is as follows: 1. Investigate the implication of multiple blood feedings observed in mosquitoes in field conditions. How does the AA/TOR pathway work in free-living mosquitoes with multiple blood feedings? The hypothesis to be tested is that well-nourished larvae, such as in laboratory culture, produce large-sized females able to complete this phase; poorly nourished larvae, which occur in various conditions in the field, produce small-sized females that require two or even three additional blood meals to complete the previtellogenic development that is required for the female mosquito to activate vitellogenesis and egg development via the AA/TOR signaling pathway. 2. Genome-wide screening for targets of AA/TOR. Our knowledge about the targets of this pathway is still limited to a few genes. It is apparent, that blood meal activation of the AA/TOR pathway has a major effect on multiple processes in the mosquito. In order to understand the extent of these events underlying the AA/TOR signaling, I propose to utilize microarray studies complemented with the tools of reverse genetics that permit the specific knockdown of a gene of interest. 3. Investigate the role of the insulin/PI3K-signaling pathway in mosquito reproductive biology. Nutrient- and insulin signaling coordinate protein synthesis to regulate cell growth, development, fecundity, metabolic homeostasis and life span in multicellular organisms. We need to determine the role of the insulin/PI3K-signaling pathway in mosquito reproductive biology relative to blood feeding. 4. Genome-wide screening for targets of the insulin/PI3K-signaling pathway. At present we have no direct candidate genes for the insulin/PI3K-signaling pathway. In order to identify the repertoire of genes controlled by this pathway during mosquito egg maturation, I propose to utilize microarray studies complemented with the tools of reverse-genetics that permit specific knockdown of a gene of interest.